Fastener members, having a tubular shank portion and a flange portion, are known and are commonly referred to as tee-nuts. In this specification, the term "tee-nut" is used to describe such fastener members. In particular, the tee-nuts, substantially as shown in U.S. Pat. No. 3,480,061, are widely used in automatic setting machines, in the furniture industry.
Such tee-nuts are formed of sheet metal, and provide a flanged portion, and a threaded sleeve, and a plurality of fastening teeth, all formed out of a single portion of sheet metal.
Typically, such tee-nuts are used, for example, in bed frames, for fastening the legs of the bed to the frame. They do have a variety of other uses, both in furniture, and in many other industries.
The industry provides automatic setting machines, as shown in U.S. Pat. No. 3,460,217. Typically, the machine will incorporate a power drill, for drilling a hole in a wooden work piece, after which the drill is automatically removed, and a tee-nut is automatically supplied to the wooden work piece, and is then forced into it, with the sleeve of the tee-nut in the pre-drilled hole. The teeth on the flange of the tee-nut are embedded in the wood around the hole and thus secure it in position.
It is of course essential that such automatic setting machines shall be supplied with a continuous and reliable feed mechanism, for feeding the tee-nuts to the work piece. Any tendency for the feed mechanism to jam will result in downtime on the setting machine, with the resultant loss in production.
The feed mechanism for supplying such tee-nuts to the work piece involves a hopper, and a track in which the tee-nuts are fed in line from the hopper to the work piece.
Usually, the tee-nuts are fed into the track in one orientation, and the track then is curved through one hundred and eighty degrees, so as to bring the tee-nut to the work piece in the reverse orientation. The track thus functions essentially to upset or reverse the tee-nut.
In so doing, it is necessary for the track to be curved around an arc usually of about one hundred and eighty degrees.
When travelling in the track, the tee-nuts have a tendency to override one another as they move around the curved portion of the track, and this has been a frequent cause of misfeeding and jamming of the feed mechanism.
One solution to this problem would be simply to reduce the clearance in the track so that the tee-nut flanges could not tilt relative to one another. However, while this might be the ideal solution, it has not been found to be practicable. The track is usually manufactured out of a piece of straight bar stock, by milling a pair of grooves in the bar, which grooves receive opposite sides of the flange. The bar is then carefully bent into the appropriate shape.
It is therefore necessary to leave a relatively great degree of clearance in the track, so as to allow for the bending of the track.